Pneumatic-despatch-tube apparatus.



E. A'. FORDYOE.

PNEUMATIC DESPATGH TUBE APPARATUS.

APPLIGATION TILED PEBA, 190'7 1,044,877, Patented Nov. 19, 1912.

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APPLICATION FILED PEB.4, 1907.

Patented N0v.'19,- 1912.

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COLUMBIA PLANOGRAPH CO" WASHINGTON, D. c.

UNHED STATES PATENT OFFIQE.

EDMOND A. FORDYCE, 015 BOSTON, MASSACHUSETTS, ASSIGNOR TO AMERICAN PNEU-MATIC SERVICE COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION OFDELAWARE.

PNEUMATIC-DESPATCH-TUBE APPARATUS.

Specification of Letters Patent.

Patented Nov. 19, 1912.

To all whom it may concern:

Be it known that I, EDMOND A. FORDYOE, of Boston, in the county ofSuffolk and State of Massachusetts, have invented certain new and usefulImprovements in Pneumatic-Despatch-Tube Apparatus, of which thefollowing is a specification.

This invention relates to improvements in pneumatic despatch tubeapparatus, and particularly to those normally closed sys tems wherein avacuum is maintained and the carriers are propelled therethrough by theadmission of atmospheric pressure.

The object of my invention is to supply a simple and efiicient devicewhich will permit the admission of atmospheric pressure directly throughthe bell mouth when a carrier is to be despatched and automatically timeand control the admission of said atmospheric pressure, and which devicecan be thrown out of communication with the pressure in the system forthe purpose of inserting carriers into the bell mouth.

In the accompanying drawings which illustrate a construction embodyingmy invention, Figure 1 is a diagrammatic view of an ordinary vacuumsystem showing the device in controlling connection with the bell mouth;Fig. 2 shows the device opened for inserting a carrier into the bell,mouth; Fig. 3 is an enlarged sectional view of the device showing thenormal or closed position; Fig. 4 is a similar view to Fig. 3 showingthe mechanism in open position admitting air for driving carriers.

Like letters of reference refer to like parts throughout the severalviews.

Referring to Fig. 1: A is a transmission tube connecting the bell mouthB at the central station controlled by the device (Zn-with the terminalD at the substation having the usual delivery valve F1. l

G is a transmission tube for the return of carriers having the ordinarydespatching inlet valve F and connecting the terminal D with thedelivery terminal H at the central station. The terminal H isconnectedwith avacuum drum L by a pipe K; connecting the pipe K with the casing Iwhich is mounted upon the bell mouth B is a small vacuum tube M. Theouter swinging valve 3 is pivoted to the casing I on the pin, 2 and isnormally held closed by a spring 8 and latch 4 which is adapted toengage the catch 6. This latch 4 is pivoted to the outer valve 3 at 5and is held closed by spring 7.

Mounted in the outer valve 3 is a diaphragm 9 held in position by a ring10. Springs 11 are attached to the diaphragm 9 and to the pins 12 fixedin the valve 3. The diaphragm 9 is slidably mounted over the hollowvalve stem 13 and between the shoulder 37 and collar 36 and which stem13 is centrally mounted and slidable in the plate 14 mounted in thevalve 3. The leather valve 15 is carried on the outer end of the valvestem 13 and normally closes the bell mouth B (Fig. 3). The movement ofthe valve 15 is limited by the adjustable screw 16 held in posit-ion bythe check nut 17 The inclosed chamber 18 is controlled by a timing screw19 adapted to regulate the passage 20. The chamber 21 between thediaphragm 9 and the plate 14 is adapted to communicate with the vacuumtube M through passages 22 and 23 when the outer valve 3 is closed (Fig.3) and with the atmosphere throughpassage 22 when the valve 3 is opened(Fig. 2). The exhaust of air from chamber 21 is timed by the adjustablescrew 24 and leakage is prevented by the rubber gasket 25. The chamber27 is open to" the atmosphere through apertures 26. Inclosing anaperture in the valve 15 is a diaphragm 28 held in position by theretaining ring 29 andexposed to the vacuum in the bell mouth B onone'side and to the atmosphere in chamber 27 on the opposite side.

A valve stem 30 connected with the diaphragm 28 carries the piston valve31 which is mounted in the hollow valve stem 13 and normally closes theport 32. A spring 33 is confined between the piston 31 and a bushing 34.A port 35 connects the hollow valve stem 13 with the chamber 27 Theoperation is as follows: The operator in despatching a carrier from thecentral station to the sub-station grasps the handle or latch 4releasing the same, and raisin the valve 3 inserts the carrier into thebell mouth B (Fig. 2). The opening of valve 3 opens the passage 22admitting air to the chamber 21 breaking the vacuum therein. The springs11 now pull the diaphragm 9 back as fast as the air in the chamber 18 isexpelled through the passage 20. When the diaphragm 9 has slid upon thevalve stem 13 a short distance it engages collar 36 and through thevalve stem 13 moves the V valve 15 backward until the collar 36 engagesthe screw 16. In the meantime, the

air entering the bell mouth B drives the carrier through the tube A andthe operator has released the valve 3 which by tension of spring 8closes, the latch 4E engaging the stop 6 locking the valve closed. Theparts are now in the position shown in Fig. 4 with the air enteringthrough apertures 26 as shown by arrows. The vacuum now acting throughthe tube M 22, gradually exhausts the air in'the chamber 21 and when thediaphragm 9 has been pulled along the valve stem 13 a short distance, itengages the shoulder 37 and the valve 15 now begins to close. By thetime the valve 15 has closed, the carrier has discharged through thevalve E at the sub station. This timing of the closure of the valve 15is regulated by the screw 24:.

In returning a carrier from the sub station to the central station, theinlet valve F is opened and the carrier inserted into tube G. Theopening of valve F breaks the vacuum in tube A and releases the dia-'phragm 28 at the bell mouth B, the spring 33 causing the piston 31 tomove back uncovering the port 32 and admitting air from chamber 27through the port 35 and port 32 to the chamber 21 and breaking thevacuum therein. The valve 15 is now opened in the manner hereinbeforedescribed and the air is admitted to the system (see Fi 4). As soon asthe operator closes the va ve F, the slight vacuum due to the resistanceto the air entering the bell mouth B draws the dia phragm 28 outwardmoving the piston 31 and closing the port 32. The air nowcbegins toexhaust from the chamber 21 through the tube M until the valve 15 isclosed and the carrier has discharged through the valve J at the centralstation. The vacuum at the bell mouth B when the valve 15 is open may beregulated by the screw 16 which limits the opening of said valve andincreases the resistance to the air entering. The lost motion of thediaphragm 9 between the shoulder 37 and collar 36 is to prevent themomentary breaking of the vacuum in the tube A when a carrier dischargesfrom reopening the valve 15.

Having thus described the nature of my invention and set forth aconstruction embodying the same, what I claim as new and desire tosecure by Letters Patent of the United States is:

1. In pneumatic despatch tube apparatus a carrier transmission tubeprovided at one end with a mouth to receive carriers, an air-exhaustpipe communicating with the other end of said tube, a by-pass leadingfrom a point adjacent the mouth of the transmission tube to theair-exhaust pipe, a hinged head normally closing the mouth of thetransmission tube and comprising inner and outer chambers with the innerchamand passages 23 and ber having a comparatively large opening to theoutside air and theouter chamber having a comparatively restrictedopening to the outside air and said outer chamber also having a passageto communicate'with said by-pass when the head is closed and tocommunicate with the outside air when the head is open, a valvemovably'mounted in the inner chamber of the head opposite the mouth ofthe transmission tube, resilient means normally holding the valve awayfrom the mouth of the transmission tube, and a diaphragm in the outerchamber of the head between the restricted openingof said chamber to theoutside air and the passage of said chamber to the by-pass, saiddiaphragm being connected with said valve to move the latter against theaction of said resilient means to close the mouth of the transmissiontube when the air is exhausted from the outer chamber through thelatters passage to the bypass when the head is closed.

2. In pneumatic despatch tube apparatus, a carrier transmission tubeprovided at one end with a mouth to receive carriers, an aireXhaust pipecommunicating with the other end of said tube, a bypass leading from apoint adjacent themouth of the transmission tube to the air-exhaustpipe, a hlnged head normally closing the mouth of the transmission tubeand comprising inner and outer chambers with the inner chamber having acomparatively large opening to the outside air and the outer chamberhaving a comparatively restricted opening to the outside air and saidouter chamber'also having a passage to communicate with said by-passwhen the head is closed and to communicate with the outside air when thehead is open, means to regulate the flow of airefrom the outer chamberthrough the passage to the by-pass, a valve movably mounted in the innerchamber of the head opposite to the v mouth of the transmission tube,and a diaphragm in the outer chamber of the head between the restrictedopening of said chamber to the outside air and the passage of saidchamber to the bypass, said diaphragm having a sliding connection withsaid valve to move the latter against the action ofsaid resilient meansto close the mouth of the transmission tube when the air is exhaustedfrom the outer chamber through the latters passage to the by-pass whenthe head is closed. V e

3. In pneumatic despatch tube apparatus,

a carrier transmission tube provided at one end with a mouth to receivecarriers, an airexhaust pipe communicating with the other end of saidtube, a by-pass leadingfrom a point adjacent the mouth of thetransmission tube to the air-exhaust pipe, a hinged hollow head normallyclosing the mouth vof the transmission tube, a partition dividing saidhead into inner and outer chambers, said inner chamber communicatingwith the mouth of the transmission tube and having a comparatively largeopening to the outside air, said outer chamber having a comparativelyrestricted opening to the outside air and also having a passage tocommunicate with said by-pass when the head is closed and to communicatewith the outside air when the head is open, a valve movably mounted inthe inner chamber of the head opposite to the mouth of the transmissiontube, a valve-stem on said valve projecting through said partition intothe outer chamber, resilient means connected with said! valve-stemnormally holding the valve away from the mouth of the transmission tube,adjustable means for regulating the movement of the valve-stem, and adiaphragm in the outer chamber of the head between the restrictedopening of said chamber to the outside air and the passage of saidchamber to the by-pass, said diaphragm having a sliding connection withsaid valve-stem to movethe same against the action of said resilientmeans to close the valve against the mouth of the transmission tube whenthe air is exhausted from the outer chamber through the latters passageto the by-pass when the head is closed.

4. In pneumatic despatch tube apparatus, a carrier transmission tubeprovided with a mouth at one end to receive carriers, an airexhaust pipecommunicating with the other end of said tube, carrier-admission meansin said tube intermediate of its ends, a bypass leading from a pointadjacent the mouth of the transmission tube to the airexhaust pipe, ahinged head normally closing the mouth of the transmission tubecomprising communicating inner and outer chambers with the inner chamberhaving a comparatively large opening to the outside air and the outerchamber having a comparativelyrestricted opening to the outside air andsaid outer chamber also having a passage to communicate with saidby-pass when the head is closed and to communicate with the outside airwhen the head is open, a valve movably mounted in the inner chamber ofthe head opposite to the mouth of the transmission tube, resilient meansnormally holding the valve away from the mouth of the transmission tube,a diaphragm in the outer chamber of the head with the restricted openingof said chamber to the outside air on one side of the diaphragm and onthe other side of the diaphragm the communication of the outer' chamberwith the inner chamber and also the passage of the outer chamber to theby-pass, said diaphragm be ing connected with said valve to move thelatter against the action of said resilient means to close the mouth ofthe transmission tube when the air is exhausted from the outer chamberthrough the latters passage to the bypass when the head is closed, asecond diaphragm mounted in said valve to be actuated by the differencesof pressure in the inner chamber and transmission tube when said valvecloses the mouth of the tube, means connected with the second diaphragmcontrolling the communication between the inner and outer chambers ofthe head to be actuated to open such communication between the chamberswhen said second diaphragm is moved by a fluctuation of pres sure in thetransmission tube occasioned by the opening of the carrier-admissionmeans inltoermediate of the ends of the transmission tu e.

In testimony whereof, I have signed my name to this specification in thepresence of two subscribing witnesses, this twenty-eighth day of JanuaryA. D. 1907.

EDMOND A. FORDYCE.

Witnesses:

MARY G. SMITH, L. G. BARTLETT.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, D. G.

